U.S. senator and past presidential candidate John McCain delivered a breathtaking body blow to mixed martial arts’ reputation in its infancy.

“Human cockfighting,” he labeled the developing sport.

MMA wore those words from a respected political figure like a scarlet letter for years, even as it successfully built sanctioning bodies, expanded to nearly every state and around the world and assumed its place on the spectrum of mainstream sports by storm.

When pressed to recall those early days, however, some of the sport’s strongest apologists reluctantly admit that maybe, just maybe, the gentleman from Arizona had a point.

“I started 12 years ago in Minnesota, where I’m from, before there was any sort of commission,” said Travis Wiuff, now a veteran of the world-famous UFC and Bellator promotions. “The fights were completely unregulated. I would stand in the cage and the promoter would point out people in the crowd who wanted to fight me.”

Fueled by adrenaline, testosterone and commonly alcohol, it was the most basic of human responses.

Think of the fan at home who watches NASCAR drivers zip around the oval at speeds close to 200 mph and mutters that it’s “just a bunch of left-hand turns.” Or the fellow out for a night of carousing with his ex-college buddies who sees the bouncer and thinks out loud, “He’s not so big.”

Funny thing is, Wiuff was that bouncer.

He wandered into a bar in the Land of 10,000 Lakes looking for a job in that capacity after dropping out of college. Someone saw the 290-pound national champion wrestler and suggested that he should train for the new caged activity that was all the rage.

The rest became history, and there was Wiuff, still catching his breath and bathed in sweat from his first bout, preparing to fight a Joe Palooka he’d never even met at a weigh-in.

“They would come into the cage with cowboy boots on, with belt buckles, what have you, and I would fight them,” Wiuff said. “It was all about putting on a good show, and I would fight three or four times a night. I didn’t have to look hard for a fight.”

A decade later, ardent fans know the feeling.

Thanks to painstaking efforts to finetune the rules that govern the sport with safety foremost in mind, MMA is contested legally almost everywhere in the United States.

“It has settled down,” Bellator CEO Bjorn Rebney said of the early hue and cry against the activity. “There was a substantial amount of it early on. Now we have unified rules regulating MMA in every state except for three.”

New York and Connecticut are the only states that have not sanctioned and regulated professional MMA. Alaska does not currently have a state commission in place to oversee the sport.

Four states — Colorado, Connecticut, North Dakota and West Virginia — do not permit amateur MMA.

Maine was relatively late to the party. A bill sponsored by State Rep. Matt Peterson, D-Rumford, established the state’s Combat Sports Authority in 2011.

That opened the door for New England Fights, a mixed martial arts promotion co-founded by Peterson and Nick DiSalvo of Massachusetts.

Fights are well matched according to the combatants’ size and experience. Prospective fighters undergo a litany of medical examinations and are forced to the sidelines for a specified time window if they are the victim of a knockout.

“Now every fighter has to show the medical chart,” Rebney said. “They require a full neurological exam and blood work before you can fight.”

Rebney’s promotion hosted a card at Androscoggin Bank Colisee in Lewiston for the first time in March.

It was a night notable for early knockouts and quick submissions — three fights ended in under 20 seconds.

An attending physician was sent to each fighter’s locker room, win or lose, regardless of the outcome. In the case of Matt Peterson’s brother Jesse, a local fighter who fell unconscious at the hands of a chokehold by Dave Vitkay, the medical personnel kept him under extended observation to ensure that he did not require further treatment.

“I can see the people who say, ‘that’s just cockfighting’ and this and that,” said Lewiston fighter Brent Dillingham, who teaches the sport out of a new gym in Topsham. “It can be a very violent sport, but the values that it instills in you really outweigh that, I think.”

Also balancing the scales are the obvious financial benefits.

Since February 2012, six MMA shows have attracted more than 15,000 total spectators to the Colisee. It’s a venerable hockey arena that once was home to the Lewiston Maineiacs, a junior hockey franchise that struggled to fill the seats despite the nightly presence of future NHL stars.

“We haven’t done a complete financial analysis yet,” Matt Peterson said. “I do know that we partner with many local businesses — Ramada Inn and Buffalo Wild Wings, for example — and they couldn’t be happier.”

Maine has discovered what Wiuff learned in that dimly lit Minnesota gymnasium many years ago.

That the sport has an Everyman appeal. The danger and risk are surely a part of it.

Wiuff shudders to consider the price he could have paid for that lesson.

“It was a lot different back then. You didn’t have to follow any rules. Nobody knew anything about it,” he said. “We didn’t have to take any blood tests or anything. I hate to even think of all the stuff I got on me. They would literally pick people out of the crowd. A lot of times they had been drinking all night.”

Although he stopped short of endorsing MMA, McCain later acknowledged in a National Public Radio interview that the sport he once targeted for banishment had evolved.

Contrary to the often brutal nature of their chosen arena, fighters are thoughtful and respectful when confronted with criticism.

They encourage doubters to watch them between fights and to examine what the sport has done to police itself before making any blanket pronouncements.

“The fight itself is very violent,” Dillingham said. “It’s fast-paced. The thing about it is, nobody gets to see all the training behind it.”

“People talk about things like the cage and say that it looks barbaric,” added Peterson. “That cage is there for the fighters’ protection and the fans’ protection. If they were doing all these things in a ring with ropes, they would be falling over the place.”

Wiuff, the victim of a first-round knockout in his March visit to Lewiston, doesn’t regret the humble beginnings.

But you’ll never catch him reminiscing about those nights of impromptu, glorified street fights as glory days.

“It was a lot different back then. You didn’t have to follow any rules. Nobody knew anything about it,” Wiuff said. “Nowadays there is a commission in almost every state. It’s obviously much more safe. It’s much more of a sport.”